Cory Catching carefully!

[AdoraBelle Dearheart]

No. I use green nets for most fish and the white fine mesh nets for catfish and loaches. The fine mesh stops them putting their entire pectoral fin through the gaps and getting tangled up. If that happens you either cut the net off the fin or leave the fish and net in a container of water and when the fish relaxes, it usually comes out of the net.

The other way to get them out is a square plastic container put in the aquarium and use a net to guide them into the container. Then lift them out.

Okay, I'll do my best to catch them in the tupperware type tubs, it worked well for the three I had to move today. But this is really reassuring that if I need to resort to a net, like when I need to catch a load of the pygmies, that it will usually be okay, and not to panic too much if one does get trapped. Thank you so much! Your experience and advice is really helpful, and so appreciated! I'll have to find a cat for you...

I inherited a couple of yoyo loaches from my dad's tank, and loved them, but they are certainly fast, elusive and smart! I can imagine how tough they are to catch. So inquisitive too. I had to rescue one of them when the filter intake tube had fallen off and went to the bottom. Chunky girl wedged herself in there and I had to tip her out of the pipe since family was convinced she was stuck. I think she just liked it as a hidey spot.
I remember seeing a staff member at my LFS once, he'd spent more than an hour trying to catch a batch of kuhli loaches. I didn't see him catch a single one while I was there, he was so frustrated! He was complaining loudly about why they'd put them in a tank with thick sand! haha

 

[Colin_T]

I think barbels means those whisker type appendages on their face that they use to search for food. I'm determined to find out what their defensive spines/barbs are called!

The spine on the side is the pectoral fin ray.
The spine on the back is the dorsal fin ray.

Each fin has a number of rays (bones) in and the first fin ray is thicker than the others. It is usually the first pectoral fin ray that gets tangled up in nets.

 

[Colin_T]

Yoyo loaches aren't hard to catch. Put some lengths of pvc pipe in the tank and when they go in the pipe, put a net on one end of the pipe and lift the other end up. Try to keep the loach in the pipe so they don't spike you or get tangled in the net.

 

[AdoraBelle Dearheart]

You are correct. Heres a quote from some random website:
"To protect themselves from predation, Corydoras have evolved serrated spines in their dorsal and pectoral fins that can be locked in place when threatened. Furthermore, the pectoral spines, and in some cases the dorsal spines, are associated with so-called axillary glands that open at the base of the spines. "https/aquazone-indo.com/index.php/2021/10/19/keen-on-corys/#:~:text=To protect themselves from predation,the base of the spines.

Cant find the scientific name tho...

Nice, thank you for finding that! I'm gonna stick to calling them spines then

I need to do some proper research on the anatomy and physiology of cories and loaches, they're really fascinating. Like, cories are bumbling puppy dog fish. And yet they have these spines that aren't really advertised as "keep away", but can do real damage. I've also heard that they can release some kind of toxin as a last resort when they're really terrified? Stories of them releasing this toxin or something while bagged or in a tank, and all the fish dying, including the one who released it. Have no idea whether that's even true. You certainly don't see it crop up as a question or discussion.

@Colin_T I think I remember you saying some time that in all your years working with fish, you'd never come across this problem. So these things make me doubt that they even have this defence mechanism. Oh, and botia have spines too? I didn't know that either! So much to learn in this hobby.

 

[dhjaksu]

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Hi guys!
I'm having trouble with safely catching cories. Have heard never to use a net, since their defensive barbs can get caught in the netting and injure them. Makes sense! But really struggling to find a good technique and equipment to move month old cory fry, pygmy cories, and bronze cories of different sizes. When I've searched youtube vids, can't find any specifically about how to catch cories (and plecos, since I'll need to move mine soon), and all the vids I found where someone was transferring cories, they'd used a net.
I had to rehome some young pygmies recently since my tank was STOCKED, and they're still spawning - I asked a hobbyist friend of mine who was taking a batch, what the best way to catch them was. He suggested a tupperware, trapping the cory against the glass and moving it up. In my heavily planted tank, this proved impossible since I needed to catch 16 of them, and the old, young and mid-sized are all in a breeding colony, so I needed to catch large batches and move to another container to sort which would return to the tank and which would go to new homes. I also tried using a large deep disposable cup, hoping it being deeper would stop them escaping like they did with the tupperware. But fish dodged around it, only managed to catch one that way! I was worried about their stress levels, herding them gently around the tank with my hand to drive them towards the tub/cup, but pygmies spook easily, and having to do it repeatedly... I hate stressing fish out so much, especially when they then have to go through the stress of acclimating to a new home right after...

Friend said that if you resort to a net, then put some sand in the bottom of the net, so I ended up doing that. But one of the pygmies I kept was injured, had a bloody spot on his side where the barb would be. Felt awful, and frustrated! Fortunately, the fish gradually healed and seemed okay, no losses. And the eight youngsters I gave to my friend ended up spawning the day after they were introduced into their new tank But I never want to hurt one by catching them again.

When I take down my large cory tank, I plan to drop the water level really low before attempted to catch the cories. Not a problem if the tank is emptied of plant and hardscape. But the trouble with catching a few individuals from a heavily planted established tank, is that dropping the water level just leaves a dense mass of plant matter for them to hide in, and no room to move the container around to catch in.

There must be better ways, teach me! Share your catching wisdom, or any videos/articles you recommend!

I've never had issues catching corys with a net

 

[itiwhetu]

I think nets are the easiest and least stressful way of catching fish. If the fish are relaxed there shouldn't be a problem.

 

[Lynnzer]

A word of caution on the Sterbia. I had to catch 4 of them in my own tank recently. I managed with 3 of them by waiting until they disappeardd into their hideaway tunnel but the 4th was a problem. I managed to net it but it got stuck in the mesh and when i tried to pick it out it exuded loads of slime that covered my fingers and the gills of another fish that was in the net at the same time. Try as I might, I just couldn't remove the slime from the gills and the fish, I think, died. I say "think" because all I could do was put it back into the tank as being out of water was worse for it than potentially not being able to use its gills.
I was surprised at the amount of slime the Sterbia produced It was a bit like a hagfish.

 

[itiwhetu]

A word of caution on the Sterbia. I had to catch 4 of them in my own tank recently. I managed with 3 of them by waiting until they disappeardd into their hideaway tunnel but the 4th was a problem. I managed to net it but it got stuck in the mesh and when i tried to pick it out it exuded loads of slime that covered my fingers and the gills of another fish that was in the net at the same time. Try as I might, I just couldn't remove the slime from the gills and the fish, I think, died. I say "think" because all I could do was put it back into the tank as being out of water was worse for it than potentially not being able to use its gills.
I was surprised at the amount of slime the Sterbia produced It was a bit like a hagfish.

I've never heard of this with Cory's

 

[Deleted member 149562]

I have always used green nets...2 of them...one to coax and the other lying in wait to catch

I only had an issue with one female Pepper Cory in many years of keeping Cories....she didn't get stuck in the net but she definitely showed her displeasure at being caught by stabbing me in the finger whilst transferring from one aquarium to another....she was fine in the net and once in the new aquarium....my finger smarted for a while.

 

[Colin_T]

@Colin_T I think I remember you saying some time that in all your years working with fish, you'd never come across this problem. So these things make me doubt that they even have this defence mechanism. Oh, and botia have spines too? I didn't know that either! So much to learn in this hobby.

I have come across the problem of Cories spiking nets (seen coworkers with Cories stuck in nets) but they don't do it very often and never do it with fine mesh nets. Pictus catfish and loaches on the other hand always stick their pectoral fins out and get tangled up in the green nets.

Loaches have small spines on the side of the face and these get caught in nets as well as their pectoral fins. Again this is mainly an issue with the course green fish nets. The fine mesh white nets don't allow the pectoral fin rays to go through the netting and they don't normally get their fins caught. If their fins do go through the net, it is usually only a couple of mm and comes out easily when the fish settles down. But the spikes on the face are the ones to look out for.

If anyone keeps a marine tank, surgeon fish (tangs) have spines on their caudal peduncle region (where the tail meets the body), and these get tangled in nets too.

 

[AdoraBelle Dearheart]

I think nets are the easiest and least stressful way of catching fish. If the fish are relaxed there shouldn't be a problem.

Thing is, cories are rarely relaxed when being caught! They start panic swimming and breathing hard almost immediately. I always feel so sorry for them when you release them and they sit frozen on the sand, panting for a bit!

The pygmy cories are particularly difficult. Being so small and fast, and I'd say more easily spooked than the bumbling bronzes. They panic and swim frantically much more easily.
I think next time I'll give myself more time, so if I haven't caught enough on the first 3-4 sweeps, I can back off and let them chill a bit before trying again.
You never know with catching fish. Sometimes it goes well and it's easy, like when I caught the three bronzes yesterday, other times it's a frustrating nightmare. Bound to have good and bad days I guess!

A word of caution on the Sterbia. I had to catch 4 of them in my own tank recently. I managed with 3 of them by waiting until they disappeardd into their hideaway tunnel but the 4th was a problem. I managed to net it but it got stuck in the mesh and when i tried to pick it out it exuded loads of slime that covered my fingers and the gills of another fish that was in the net at the same time. Try as I might, I just couldn't remove the slime from the gills and the fish, I think, died. I say "think" because all I could do was put it back into the tank as being out of water was worse for it than potentially not being able to use its gills.
I was surprised at the amount of slime the Sterbia produced It was a bit like a hagfish.

Wow, I've never heard of this with cories either! I'll be moving my six sterbai in the next few weeks too...
@Colin_T Have you ever heard of this? Perhaps it was the excess mucus that fish tend to produce when their skin is injured or irritated?

 

[Colin_T]

All fish naturally have a mucous coating over their body but I haven't heard of Corydoras producing excessive amounts so it or other fish can breath.

 

[Teresa R.]

I've had cories do this only once. I was bringing some (2 or 3) home from the store and they were unusually agitated. By the time I got home, some looked pretty bad. Since I had never heard of this poison release, I put them into the tank; I don't think they all died. Store replaced the ones that did, and the replacements had no trouble.
I found an article about this (I searched with the words "corydoras cories defensive slime"). tl;dr? If you are transporting cories, bring along an extra container of water, so you can transfer them to clean water if this happens. And if it does, don't just empty the bag into your aquarium (including the poisoned water) like I did. Here's the link:
Self-poisoning: A Damaging Defense Mechanism

 

[Gypsum]

I get to have fun with cory moving tomorrow. Ugh. Faffing with our tank set-up. Two years after we bought our initial batch of CW045s, the LFS had them again. We had four, originally, and lost one, so now we have three. We picked up three more today and put them into the tank where Everything Breeds. Metae, habrosus, and the A. spilotus until we never wanted to see an A. spilotus fry again. Tomorrow's project is catching our old three CW045s, who live in the Tank that Never Breeds (due to Raphael catfish), and shifting them into the other tank.

 

[AdoraBelle Dearheart]

tank where Everything Breeds. Metae, habrosus, and the A. spilotus until we never wanted to see an A. spilotus fry again.

This bit made me laugh!
Congrats on the new fish! Please please snag a couple of photos while you're having fun shifting everything about tomorrow

Will you be using nets to catch the cories?